For many years, the assignee of the present patent application has made and sold large numbers of flat film-type power resistors that are fully encapsulated in a silicone molding compound. These resistors are free-standing, not being mounted in engagement with any chassis (heatsink). Thus, with such resistors, there is no danger of shorting through or arcing to the chassis. The indicated free-standing power resistors that have long been sold by applicant's assignee have power ratings of either 0.5 watt or 0.75 watt. One such free-standing power resistor is shown in FIG. 8. A transfer-molded silicone body is shown in phantom lines. An aluminum oxide ceramic chip is the back element (in the drawing), and has a back surface spaced from the back surface of the silicone body. On the front of the chip are screen-printed traces, resistive film and glass. The indicated leads are soldered to the traces.
The present resistor combination has a power rating of 15 watts, yet the physical size of the resistor (surface area of one of the two parallel sides of the entire resistor) is only a little over three times that of the indicated 0.75 watt free-standing resistor.